templates/default/jenkins/plugins/locale.xml.erb
<?xml version='1.0' encoding='UTF-8'?>
<locale plugin="locale@<%= node['jenkins-server']['plugins']['locale']['version'] %>">
<systemLocale><%= node['jenkins-server']['plugins']['locale']['system_locale'] %></systemLocale>
<ignoreAcceptLanguage><%= node['jenkins-server']['plugins']['locale']['ignore_accept_language'] %></ignoreAcceptLanguage>
</locale>